A double tapped 1001 samurais is the best one up there guarenteed (Wunderwaffe aside). The only problem is that it runs out of ammo fast (no not because of double tap it runs out fast either way) but it will kill zombies the fastest. Oh and I consider the 24 bore long range, Gut-Shot, The Penetrater, and Armageddon not comparable to fully automatic upgraded guns. I didnt say the Snuff box because no ones gotten the sawnoff shotgun yet (with proof). Maybe The Eviscerator is better but again no ones gotten the Type 99 yet.
ptrs upgraded i played with it from round 1-28 and hit 1 shot whole game,the flamethrower work well because never ran out of ammo ( i was covering a window soo yea)